Grinding wheel truing apparatus



Allg 4, 1953 o. E. HILL 2,647,504

GRINDING WHEEL TRUING APPARATUS Y Filed Sept. 8, 1950 4 Sheets-Sheet l A www Htorney Aug. 4,-1953 o. E. HILL 2,647,504

GRINDING WHEEL TRUING APPARATUS Filed sept. 8, 1950 4 sheets-sheet? @WM mea Hfforne Aug. 4; 1953 o. E. HILL 2,647,504

GRINDING WHEEL TRUING APPARATUS Filed Sept. 8, 1950 4 Sheets-Sheet 5 Hol 77 BOZ 03 Aug 4 1953 o. E. HILL l 2,647,504

GRINDING WHEEL TRUING APPARATUS Filed sept. 8, 195o 4 sheets-snee: 4

.T1/Vektor O/ VA E. /L//LL o Mmmm flfco Mey Patented Aug. 4, 1953 @BINDING WHEEL 'riaiuNG APPARATUS Oiva E. Hill, West Boylston, Mass., assigner to Norton Company, Worcester, Mass., a corporation of Massachusetts Application September 8, 1950, Serial No. 183,775

10 Claims.

The invention relates to a grinding wheel truing apparatus, and more particularly to a truing apparatus for truing different diameters on a single wheel or a plurality of adjacent Wheels.

One object of the invention is to provide a simple and thoroughly practical truing apparatus for truing e. multi-diameter grinding wiheel. Another object is to provide .a hydraulically-actuated electrically-controlled truing apparatus successively to true a plurality of different diameters on the periphery of a grinding wheel. Another object is to provide truing apparatus with a hydraulically-actuated cam mechanism automatically to position the truing tool successively to true multiple adjacent diameters on either a single grinding wheel or a, plurality of adjacent grinding wheels. Another object is to provide a hydraulically operated traverse mechanism for a truing tool and a hydraulically operated cam mechanism actuated in timed relation therewith successively to position the truing tool for truing a plurality of varying diameters on a grinding wheel. OtherI objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements and arrangements of parts as will be exemplied in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing-s, in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. l is a front elevation of the grinding wheel truing apparatus; 5

Fig. 2 is a plan View of the truing apparatus;

Fig. 3 is a fragmentary vertical sectional view, on an enlarged scale, taken approximately on the line 3-3 of Fig. 1;

Fig. 4 is a horizontal sectional View, on an enlarged scale, taken approximately on the line 4-4 of Fig. 3, showing the pawl and ratchet feed mechanism for the truing tool;

Fig. 5 is a fragmentary horizontal sectional view, on an enlarged scale, taken approximately on the line 5-5 of Fig. 3, showing the anti-friction support for the truing tool holder; l

Fig. 6 is a combined hydraulic and electrical diagram of the control mechanism for the truing apparatus; i

Fig. 7 is a diagrammatic view showing the relative position of the parts after the truing tool has traversed across the first portion of the grinding wheel to be trued;

Fig. 8 is a similar diagrammatic View showing 2 the relative position of the parts after the truing tool has been positioned to true the second portion of the grinding wheel; and

Fig. 9 is a similardiagrammatic view showing the relative position of the parts after the truing tool has completed a traversing movement across the entire face of the grinding wheel to be trued;

The truing -apparatus has been illustrated in the drawings as applied to a grinding machine having a rotatable grinding Wheel I0 which is partially surrounded by a wheel guard II. The grinding wheel I0 may be a single grinding wheel, or as shown in Fig. 6 spaced grinding Wheels having surfaces Illa, IIlb, Illc, Illd, loe, I 0f and I 0g of diiierent diameters to be trued. The wheel guard I I serves as a support for an upwardly'extending bracket I 2. The bracket I2 supports a `slide base I3 which is xedly mounted thereon by a plurality of screws I3a (only one of which has been illustrated in Fig. 3). The slide base I3 is provided with a dovetailed slideway I4. A longitudinally movable slide I5 is provided with dovetailed slideways which mate with the slide-` way .I4 to facilitate a longitudinal movement of the slide I5 in a direction parallel to the axis of rotation of the grinding wheel I0.

A hydraulically operated mechanism is provided for traversing the slide I5 longitudinally comprising a hydraulic cylinder I6 which as shown is formed integral with the slide base I3.

The cylinder I6 contains a slidably mounted piston I'I mounted on one end of a piston rod I8. The other end of the piston rod i8 is fastened to a bracket I 9 formed integral with the slide I5. When fluid under pressure is passed through a pipe 20 into a cylinder chamber 2| Fig. 6), the piston I7 together with the slide I5 Will be moved longitudinally toward the right. During this rmovement of the piston Il, fluid within a cylinder chamber 22 may exhaust through a pipe 23.

The slide I5 serves as a support for a transversely movable vertically arranged sleeve 25. A spindle 26 is mounted within the sleeve 25 and supports a truing tool holder 2l' at its lower end. The truing tool holder 2l is provided with a di-amond or truing tool 28 which isarranged to true the periphery of the grinding wheel as will be hereinafter described.

The sleeve 25 is preferably supported by a plurality of anti-friction rollers to facilitate free movement thereof ingenerating the desired form or shape on the grinding wheel. The sleeve 25 is supported adjacent its upper end by .a plurality of anti-friction rollers29, 3D and 3|. The rollers 2S, 30 and 3l are supported by studs 32, 33 and "it respectively. The stud 32 is preferably provided with an eccentric 32a to facilitate adjustment of the roller 29 toward and from the sleeve 25.

The lower end of the sleeve is similarly supported by a plurality of anti-friction rollers, only one of which haslbeen illustrated in. Fig. 3. The roller 35 is supported by an eccentric stud 36 having an eccentric 36a to facilitate adjustment of the roller 35. The other two rollers in this set are arranged in an identical manner with the arrangement shown in Fig. `5, consequently these rollers have not been illustrated in the drawings,

The upper end oi the sleeve 25 is provided with an integral flange lll which-'serves asa support for a bracket 4I. The bracket M isprovided with a lug l2 having parallel side faces which are engaged by a pair 'of spaced anti-friction rollers llt and te. "The rollers *43 and @lli are supported by studs 45 and A6 which 'are inturn xedly .mounted on Atheslide l5. The rollers 43 and M serveas aguide for 4the sleeve 21S-as it is moved vertically during'operation.

A.The truing tool spindle 2B is slidably keyed within a central aperture within 'the sleeve 25. In orderto facilitate adjustment of the truing tool .2B towardand from the periphery of -the grinding wheel vbeing trued, a nut and Vscrew feeding mechanism is provided comprising a feedscrew l! formed on the upper end ofthe spindle 25. The screw 50 is surrounded by a nut 5l which is rotatably supported on the upper end-oi the-flangedportion flll'of 'the sleeve 25. A gear .52 is keyed to the nut '51. vThe gear 52 meshes with a pinion'e.mounted on the upper end .oi a vertically arranged rotatable shaft '54. The .shaft i is rotatably mounted vwithin the braclretfll and is providedat its lower end with a manually operable hand wheel'. It will be readily apparent v:from the foregoing disclosure that rotation .of the hand wheel'll will be transmitted .through the shaft 5fl,the pinion 53, the gear 52, to rotate the nut 45| and thereby to impart an axial adjustment of the `truing tool spindle 2S.

ln ord-er .to hold the nut 5I in adjusted position, aserrated Wheel 58 is xedly'mounted on the upper .end or the shaft '54. A spring jpressed pawl ,5l .mounted on the bracket lll lis arranged to engage the serrated wheelo and thereby to hold vthe feed nut 5l in adjusted position.

In order to .steady the upwardly 'extending portion .of the feed screw 5D, an'arm lll is clamped around a cylindrical surfaceformed'on the upper end of the Iscrewlill l(Figs. .l and 2l. The right hand .end of thearm lll is provided with a pair of Yspring pressed balls which ridein lavertically arranged groove 43 formed in a vertically extending bracket-t8. The bracket `Il!) is nxedly mounted on the flange El) of the sleeve '25.

lt is desirable to `provide an automatically-actuatedmechanism for imparting a feeding movement to the .truing 'tool vat the end of its longitudinal traversing movement. This ispreferably accomplished .by .means .of a pawl and ratchet mechanism comprising a ratchet wheelll which iskeyed to the .nut 5l `(Fig. 3). Arpawl carrier (Figs. 3 and 4) is .rotatably vmounted on the nuti and is provided with a leedpawl '60. The iced pawl .Se is supported by a stud 6I fastened to thepawl carrier 59. .A compression spring 6.2 .serves .normallyto maintanthe .pawl 60 in operative engagement with the ratchet Wheel 58, A

manually operable rotatable eccentric 63 is provided to facilitate rocking the pawl lill to an inoperative position if desired so as to -facilitate a manual adjustment of the truing tool spindle. A compression spring 6d normally urges the pawl carrier in a clockwise direction (Fig. 4) with the stud S5 in operative engagement with a stop surface which is fixedly mounted on the flanged portion lll of the sleeve 25.

When the slide l5 approaches the right hand end oi its stroke, the pawl carrier 59 engages an adjustable stop screw S9 which serves to rock the pawl carrier il@ in a counterclockwise direc- 'tion'so as to impart a predetermined down feeding movement to the truing tool 28. The stop screw '655 is carried by a bracket 6250, which is adjustably clamped on the upper surface o the bracket l2 by clamping screws Gti). The clampin screws till) ride a T-slot (ille formed in the upper surface of the bracket l2. The pawl carrier 59 is provided with a laterally extending arm which'supports a roller 6l. The roller Sl is arranged in the path of a cam '63 so that when the slide l5 approaches the left hand end position, the pawl carrier 59 is actuated to impart a predetermined down 'feeding movement to the truing tool E8. The cam Gil is kformed on a bracket tim which is adjustably mounted on the bracket lil. A clamp bolt Elib carried by the brach/ct 68d rides in the T-slot 69e.

An automatically actuated mechanism is provided for positioning the truing tool 2B in a vertical direction to true the various diameters on the periphery of the lgrinding wheel l0. This mechanism may comprise a slidably mounted cam lil which is slidably supported on the longitudinally movable slide l5. The 'cam bar "i0 is provided with a cam face ll having a 'plurality of horizontal portions lla, lib, "Hc, lid, lle, 'Hf and 'Hg for positioning the truing tool 28 successively to true the faces ita, lill), loc, ltd, ille, lfand lUg of the grinding wheel Il). A follower` l2 is xedly mounted on the vertically movable sleeve 25 so that when the cam bar lli is moved longitudinally the 'follower will be moved in a vertical direction to impart a corresponding movement to the sleeve 25, the spindle the truing tool holder lll the truing tool 2S.

A hydraulically loperated mechanism is provided for intermittently traversing the cam bar lo comprising an hydraulic cylinder "d3 which is fixedly mounted on the longitudinally movable slide l5. The cylinder 'i3 contains a slidably mounted piston lil. The piston lil is connected by means oi a piston rod i5 with a bracket 'ES which is fixedly mounted on the right hand end of the cam bar lll. When fluid under pressure is passed through a pipe l'i into a cylinder chamber 18, at the left hand end of the cylinder T3, the piston "M will be caused to move toward the right imparting a corresponding movement to the piston rod "l5, the bracket lf3, and the cam bar l0. During this movement duid within.` .a cylinder chamber 'i5 is exhausted through a Pipe 8U.

An automatic control mechanism is provided which is operated by and in timed relation with the movement of the cam bar 'it comprising a slide bar which is also slidably mounted on the longitudinally .movable slide l5. The leit hand end oi the cam bar lil is provided with an upwardly extending bracket 82 having an adjustably mounted stop screw 83 m-ounted adjacent to the upper end thereof in alignment with the left hand end of the-slide bar Si. The bracket l@ is also provided with an adjustably mounted stop screw 84 which is aligned with the right hand end of the slide bar 8| The upper face of the slide bar 85 is provided with a plurality of scallops 85a, 85h, 85e, 85d, y85e and 85f which are arranged to engage and actuate the actuating roller 86 of a limit switch LS3. The roller 86 is mounted on the lower end of a pivotally mounted arm 88 which is arranged to actuate an actuating arm 88 of the limit switch LS3. The limit switch LSB is provided with two pairs of contacts 90 and 9| which'are normally open and 92 and 93 which are normally closed. When the slide bar 10 is indexed longitudinally by movement of the piston 14, the scalloped surface of the slide bar 85 will actuate the roller 86 to shift the contact arm of the limit switch L53 so as to make and break the normally open and normally closed contacts therein. The operation of this limit switch LS3 will be` more fully described hereinafter.

A slide bar l llis also slidably supported on the rear face of the slide |5 (Fig. 3). The slide bar |90 is arranged to move with the longitudinally movable slide 5 through a limited stroke as governed by a pair of spaced aligned stop screws I!!! and |62 which are mounted in lugs |03 and |04 respectively. The lugs |93 and |94 are iixedlv mounted on the slide base i3. The Slide bar |00 is provided with a plurality of spaced scallops |5a, |6519, |650, |6501, Ill-5e and |Ei5f. An actuating roller |66 of a limit switch LS2 is arranged to operatively engage the upper surface of the slide bar |66 (Figs. 6, 7, 8 and 9). The limit switch LS2 is xedly mounted onthe longitudinally movable slide l5. The roller |66 is sunported on the lower end of an actuating arm |66 of the limit switch LS2. The limit switch L52 is provided with two pairs of contacts |09 and H6 which are normally opened and contacts H and I |2 which are normally closed. During the initial longitudinal movement of the slide 5 toward the right, the roller 96 rides along the upper surface of the slide bar l lll) until it starts to drop into the scallop Nia which serves to actuate the limit switch LEZ in a manner to be hereinafter described. When the roller |06 moves out of a scallop onto the top of the slide bar |00, due to longitudinal movement of the slide I5, the normally closed contacts l2 open so as to break the holding circuit and thereby tc deenergize CB2. CB2 remains deenergized until the next movement of the cam bar 19 and slide bar 85 allow roller 86 to drop into a scallop to close the normally closed contacts 92.-93 of the limit switch LSB thereby energizing CR2 and again establishing a holding circuit.

A hydraulic system is provided for supplying fluid under pressure to the cylinders i6 and 13 comprising a motor driven uid pump |20 which draws fluid through a pipe 2| from a reservoir |22 (Fig. 6). The pump |20 forces fluid under pressure through a pipe |23 to a control valve |24. The control valve |24 is a shuttle-type valve' comprising a slidably mounted valve member |25 having a plurality of valve pistons formed thereon to provide a plurality of valve chambers |26, |21 and |28. The valve member |25 is also provided with a central passage |29 to facilitate eX- haust of uid through the valve |24. A pilot valve |30 is provided for shifting the valve member |26 axially by means of fluid under pressure. The pilot valve |3|) comprises a slidably mounted valve member |3| which is normally held in a right hand end position by means of a compression spring |32. A solenoid AS3 is provided vto shift 6 the valve member 3| toward the left. In the position of the control `valve |24 and the pilot valve |30, uid under pressure passing through the pipe |23 enters the valve chamber |21 and passes through a passage |35, through a chamber in the val-ve member 3| and through a passage |36 into an end chamber |31 to move the slidably mounted valve member |25 toward the left (Fig. 6) into the position illustrated. During this movement iiuid within an end chamber |38 may exhaust through a passage |39, through the pilot valve |30 and into the reservoir |22. The control valve |24 serves to pass fluid under pressure either to a control valve |45 for controlling the admission to and exhaust of uid from the cylinder 73 or to a control valve |65 for controlling the admission to and exhaust of iiuid from the cylinder I6.

In the position of the Valve |24 (Fig. 6), iiuid under pressure entering the valve chamber |21 passes through a pipe |45 to the control valve |46. The control valve |46 comprises a slidably mounted shuttle-type valve member Ml having a plurality of valve pistons thereon which form a plurality of valve chambers |48, |49 and |50. In the position of the valve |46 (Fig. 6) fluid under pressure passing through the pipe |45 enters the valve chamber |49 and passes thr-ough a passage |5| to a pilot valve |52. The pilot valve |52 comprises a slidably mounted valve member |53 which is normally held in a right hand end position by means of a compression spring |54. A solenoid S2 is provided for shifting the valve member |52 toward the left.

In the position of the valve |46 (Fig. 6) fluid under pressure passing through the passage |5| passes through a chamber in the valve member |53, through a passage |56 into an end chamber |51 to move the valve member |41 toward the left into the position illustrated in Fig. 6. During this movement of the valve member |141, fluid within an end chamber |59 may exhaust through a passage |59. The valve member |41 is provided with acentral passage |60 to facilitate passage of uid exhausting from the cylinder 13. In the position of the valve |46 (Fig. 6) Iluid under pressure entering the valve chamber |49 passes through the pipe 8D into the cylinder chamber 19 to move the piston 14 toward the left into the position illustrated in Fig. 6. During this movement iiuid within the cylinder chamber 18 may exhaust through the pipe 11 through the valve chamber |56 in the valve member |41, through the central passage |66, through the valve chamber |48 and exhaust through a pipe |6|, through a throttle valve |62 and through a pipe |63 into the reservoir |22. The throttle valve |62 serves to ccntrol the rate of exhaust of fluid from the cylinder 13 and thereby serves to control the speed of movement of the piston 14.

The control valve |65 is provided With a sl-idably mounted shuttle-type valve member |66 having a plurality of valve pistons formed thereon to provide a plurality of Valve chambers |61, |69 and |69. Fluid under pressure passing through the pipe |64 enters the valve chamber I 68 and passes through a passage |10 into a pilot valve |1I. The pilot valve is provided with a slidably mounted valve member |12 which is normally held in a right hand end position by means of a compression springr |13. A solenoid SI is provided for shifting the valve member |12 into a reverse position. Fluid under pressure passing lthrough the passage |10 passes through acharnber formed-in the valve member '112, through a passage |15 into an-end chamber |16 to move the valve member HB9 ytoward the left into the position illustrated in Fig. `6. During this movement fluid within an "end chamber |11 may exhaust throughla passage |18, through the `pilot valve |12 and exhaust into the reservoir |22. The valve member |66 is provided with a central passa'ge |19 to facilitate the exhaust of rfluid from the cylinder I6.

When lfluid under-pressure is passed through the pipe |64 intothe valve ehamberil, liuid may pass through the pipe 23 into the cylinder chamber 22 to move the piston '|1 toward the lett into the position illustrated in Fig. 6. During this movement of the piston huid within the cylinder chamber 'il 'may `'exhaust'through the pipe "2-53 into the valve chamber |59, through the central passage |13, through thevalve chamber |61 and exhaust through a pipe |90. The pipel!) is prO- vided. with an adjustable rthrottle valve 19| through which huid .may exhaust into the exhaust pipe |33 and vinto the reservoir |22. It will be readily apparent 'lromthe foregoing disclosure that the throttle valve |8| controls the rate of exhaust of iluid from 'the cylinder iii `and thereby controls the speed 'of vmovement of the piston |1.

The throttle valve 18| serves as above described to control the rate of exhaust of lluid from both 'ends of the cylinder depending upon the-position of the valve i155 to provide a relatively slow uniform speed of the tru-ing tool '28 during a'truing operation. It is ydesirable to speedup the move-ment of the truing tool during its initial idle stroke until the diamond or truing 'tool :28 moves -into operative engagement with the surface Ilia to be trued and also to speed up the movement of the truing 'tool in gaps between wheel faces such as between -faces Illa and mb. This is preferably accomplished by providing a by-pass valve |99 which is connected to icy-pass iluid around the throttle valve |B|. rIhe `Joy-pass valve |93 has been illustrated on a somewhat enlarged scale in the diagrammatic illustration in Fig. 6. This valve is a piston type `valve oorfprising .a valve stem |9| -having valve pistons |92 and |93 `formed integrally therewith. A compression spring |94 serves normally to urge the valve stem |9| in a downward direction normally to maintain the bypass valve |90 in a closed or inoperative position. The valve pistons |92 and |93 form a valve chamber |35 through which iiuid may pass from the exhaust line |86 into a pipe |96 which connects with the exhaust pipe |53 'thereby by-passing fluid around the throttle valve ll. The by-pass valve |91l is lixedly mounted on the bracket i2 .and is arranged so that the valve stem |9| lies in the path of a plurality of adjustable dogs |91, lla, and isili which are adjustahly mounted on the upper surface of the slide l5. The dogs |91., |91a and |91b are provided with elongated slots |98, |9801. and il 93h respectively. Clamping screws |99, |99afand |9619 pass through the elongated slots |93, |'9Sc and |981) formed in the dogs |91, |91a and |91b and are screw threaded into the slide l5. lt will be readily apparent from the foregoing disclosure that the dogs |91, |91a and lill; may Abe adjusted longitudinally relative to the slide l5 to vary the operation of the by-pass valve itil during the 'longitudinal movement of the slide i5. As illustrated in Figc, the valve stem |9| is on top of the dog I9? thus holding the valve I 90 lin an open yposition so that unrestricted now of 'fluid from thepipe 180, through the valve `'chamher |91 into the pipe |96 is obtained. When the slide |5 starts its longitudinal movement toward theright to move the truing tool 28 into operative engagement with the face Ilia of the grinding wheel |0, theslide l5 `moves at a rapid rate until the valve stem 19| rides down the sloping surface of the -dog |91 thereby releasing the compression of the spring |9l| which moves the valve piston |92 downwardly to close the port at the end of the pipe '|39 thereby preventing further -by-pass of fluid into the pipe |96. During the traverse of the diamond 28 across the wheel face ma, the throttle valve le! governs the speed to produce a slow uniform ltraverse of the truing tool during the truing operation. After the diamond 28 completes its pass across the face Illa, the valve stem |9| engages the slopingr face on the right hand end of the dog |91a which again serves to open the by-'pass valve to facilitate lay-passing of fluid from the pipe |86 through Avalve chamber |91 into pipe Ht. The slide I5 will then resume a rapid traverse across the gap between the wheel faces |811 and Hita. By the time thertruing tool 28 moves into engagement with the ace |913, the slide l5 will have Imoved a suicient distance so that `the valve stem l9l rides down the sloping surface at the left hand end of the dog |9la 'to again out oil the by-pass of fluid between the pipes |99 and |99 to slow down the movement of the slide to the pre-set truing speed. The slow speed 'continues during the intermittent passage of vthe truing tool across the laces lilla, 69C, ltd, ille, |92 and lily. After the diamond or truing tool 228 completes its passacross the face Ig, the valve stem |9| engages the sloping surface at the right hand end of the dog |911) to again raise the valve stem |9| to luy-pass iluid from the pipe |80 into the pipe |96 thereby speeding up the movement o1 the 'slide I5 toward the right until the slide reverses in a manner to be hereinafter described.

Electric pow-er is supplied to the truing apparatus through a pair of power lines Zilli. A main switch 23| vis provided to render the electrical controls of the truing apparatus operative or inoperative as desired. A cy-cle start push button switch 292 is provided having a holding coil 233 which ser-ves in a manner to be hereinafter described to initiate a truing cycle. A normally clos-ed limit switch LSl is xedly mounted on the slide base i3. The limit switch LS| is pro-- vided with an actuating plunger '2&5 which is arranged in the path of a lug 295 which is iixedly mounted on the longitudinally movable slide i5.

' When the longitudinally movable slide I5 approaches the right hand end of its stroke, the lug 296 engages the actuating plunger 295 to open the normally closed limit switch LS! to initiate a return stroke of the longitudinally movable slide l5 in a manner to be hereinafter described.

The parts as shown diagrammatically in Fig. 6 are at the starting position, When -it is desired to start a truing cycle, the fluid pump is fir-st started and then the main switch 23| is closed which serves to make a Circuit to energize solenoid S3 which serves to shift the pilot valve memloer I3! toward the right so that fluid within the pipe 23 passes through the valve chamber i2'i, through the passage 35, through thepassage |39 into the end chamber |38 to shift the valve member |25 toward the right so that iiuid under pressure Within the v.pipe |23 passes through the valve chamber |27 and through the pipe itil to the control valve IE5. The push button cycle control switch 292 is then closed whichserves to energize both o1" the solenoids SI and S2. When the solenoid Sl is energized, fluid under pressure from the pipe |54 is passed through the passages previously described into the end chamber to shift the valve member |55 into'a right hand end position. In this position of the valve |65, fluid under pressure passing through the pipe |54 passes through the pipe 28 into the cylinder chamber 2| to move the piston il and the slide I5 toward the right at a rapid rate to move the diamond or truing tool 28 into operative engagement with the face illu of the grinding wheel il). As the truing tool 28 moves into engagement with the face Illa, the valve stem |9| rides oil the dog lill thereby cutting oli the by-pass of fluid between the pipes |85 and |95 so that the speed of the piston il and the slide |5 is slowed down to a slow truing speed as governed by the v throttle valve ISI. The slow speed of the slide i5 continues while the diamond or truing tool 28 is passing across the face lila. During the initial movement of the slide I5 toward the right, due to frictional connections therebetween, the slide l5 moves the slide bar |95 toward the right until the slide bar engages the adjustable stop screw |52. As the slide I5 continues its movement toward the right, the valve stem i9! rides up onto the dog |9la to speed up the movement of the slide l5 and truing tool 28. When the slide I5 moves a suhcient distance so that the roller |56 of the limit switch LSZ drops into the scallop |i5a, the normally open contacts |59 and are opened to break a circuit thereby deenergizing the solenoid S3 so that the valve member returns to the position illustrated in Fig. 6. `Deenergizing the solenoid S3 cuts 01T luid pressure from the valve |55 thereby stopping the movement ofthe piston |'I and the slide |5. Fluid under pressure then passes through the pipe to the control valve |45. The solenoid S2 being energized, fluid under pressure passes through the pipe 'Il and into the cylinder chamber 'I8 to move the piston 'lli toward Athe right thereby shifting the cam bar toward the right so that the .follower "F2 rides down a sloping surface into engagement with the surface 'Hb of the cam bar l0. This movement shifts the truing tool into the position illustrated in Fig. 8 in position for truing the face lill) of the grinding wheel |00. During this movement of the cam bar 'llltoward the right, the slide bar 85 starts moving after the stop screw 83 m-oves into engagement with the left hand end thereof. When the slide bar85 starts movingv toward the right, the roller 86 drops further into the scallop 85a, so that the normally closed contacts 92 and 93 are closed to energize the relay switch CR2. The normally closed contacts ill and ||2 of the limit switch LS2, being closed, serves :as a holding circuit to maintain CRZ energized until the roller 8B starts to move upwardly as it moves into engagement with the left hand portion of the scallop 85a and opens contacts 9U and 9| of the limit switch LS3. As `the roller 88 moves upwardly, the normally open contacts 90 `and 9| are again closed to close acircuit throughV contactors of the switch CR2 to again energize "the solenoid S3 thereby cutting off fluid from the valve |46 to stop the movement of the piston 'I4 toward the right at the same time admitting iluid under-'pressure to the valve |65. The solenoid SI being energized, fluid under pressure will again be passed through the pipe 20 into the cylinder chamber 2| to start the 10 next longitudinal movement of the piston IIk and slide I5 to carry the truing tool 28 across the face lb of the grinding ywheel Il).

Longitudinal movement of the piston il' and slide l5 toward the right continues until the roller |56 starts to enter the scallop |055 in the slide bar |59 which again serves to open a circuit to deenergize the solenoid S3 so that fluid is cut oil" from the valve |65 to stop the movement of the piston i1 and slide i5 toward the right when the truing tool 28 reaches the end of the face Ib of the grinding wheel I0. When the solenoid S3 is deenergized, 'duid under pressure is again passed through the pipe |55l to the control valve |55. The solenoid S2 being energized, uid under pressure is passed through the pipe I1 into the cylinder chamber I8 to start a further movement of the piston i4 toward'the right `from the yposition illustrated in Fig. 8. When the piston 'I5 starts moving toward the right, the movement of the cam bar 'l5 toward the right causes the follower lf2 to ride up an inclined surface onto the portion Hc of the cam bar 'In so as to position the truing tool 28 for truing the face |50 of the `grinding wheel l0. During this movement of the cam bar '10, the slide bar 85 also moves toward the right. When the roller 86 moves into engagement with the next rise on the scallop h, the roller 86 is again raised to close the normally open contacts 90 and 9| thereby closing a circuit through relay switch CB2 to energize the solenoid S3 thereby cutting 01T 'the flow of uid under pressure to the valve |46 to stop the movement of the piston lli. At the same time fluid is passed through the pipe |64 to the control valve |55 through the pipe 20 into the cylinder chamber 2| to again start movement of the piston Il and slide I5 toward the right to traverse the truing tool across the face 0c of the grinding wheel During the entire right hand movement of the piston and slide I5, solenoids SI and S2 remain energized and the solenoid S3 is intermit* tently energized and deenergized to irst pass iiuid into the cylinder |6 to traverse the truing tool across a portion of the wheel, thereafter to cut fluid off from the cylinder i6 and admit fluid to the cylinder 'i3 to reposition the truing tool 28 for truing the next adjacent face on the grinding wheel. These movements are successively repeated while faces |0d, Ille, Iilf and Ig are beingtrued. After the truing tool 28 has passed across theface Ig of the grinding wheel l0, the valve stem |9| rides into engagement with the dog |9719 which again opens the bypass valvev |99 to by-pass iuid from the pipe |80 through the Valve chamber |95 into the pipe to start a rapid movement of the slide i5 which carries the actuating roller 05 of the limit switch LS2 into the position illustrated in Fig. 9 with the diamond 28 assuming the position illustrated therein. When the parts are in this position, the cam bar 'IU is stopped with the follower 'I2 in engagement with the face iig o1 the bar 'IU and the roller 86 of the limit switch LS3 is in engagement with the left hand end of the scallop 85j on the slide bar 85. As the slide |5 approaches the right hand end position, a stop lug 206 on the slide l5 engages the actuating plunger 205 of the normally closed limit switch LSI which serves to break a circuit thereby deenergizing both of the solenoids SI and S2 and also deenergizing the holding coil 263 of thestarter switch 202. The solenoids SI and S2 both l1 remain deenerg-ized during the return movement oi the piston il and slide l toward the left.

The deenergizing of the soienoids Si and S2 serves to reverse the flow of fluid to the cylinders it and TE3 so that the slide l5 and truing tool 2S move toward the left when fluid under pressure is passed thereto by the control valve i555 and the piston 'lll is similarly moved toward the left intermittently to traverse the cam bar 'it toward the left when nuid is admitted to the cylinder 'i3 by the control valve Mii. During the initial movement of the slide i5 toward the left, the slide bar B5B is frictionally moved with the slide il: until it moves into engagement with the stop screw iti, rlhis shifting movement of the slide bar serves to reposition the scallops l-if, lilc, id dd, lilac. i951)v and la so that as the roller Hl rides down the face of the scallop, the limit switch LS2 will be actuated. It will thus be seen that on the movement of the slide toward the left, the left hand edges of the scallops control the actuation of the switch L82 while on the return strolre of the slide toward the right, the right hand edges of the scallops control actuation of the roller it and limit switch L32. Similarly, during the initial movement of the piston 'lll and the cam bar l5) toward the left, the slide bar t5 remains stationary until the last motion is taken up and the stop screw 8d (Fig. 9) l engages the right hand end thereof after which the bar S starts its movement toward the left.

the slide l5 approaches its right hand end position, the pawl carrier 59 moves, into engagement with an adjustable stop screw t9 to actuate the pawl carrier and thereby to feed the truing tool 28 downwardly for the. return traverse across the `face of the grinding wheel.

During the return traverse of the slide i5 and the truing tool 28 tou-ard'the left, the solenoids Si and S2 remain deenergized during the entire stroke and the solenoid S3 is intermittently energized and deenergized as controlled by the limit switches L52 and LSE in the same manner as on the stroke of the slide l5 and truing tool 23 toward the right. During the return stroke of the slide, the holding coil 293 of the push button starter switch 232 is deenergized so that when the slidel i5 and truing tool 28 reach the extreme left hand end position after a pass across the faces. lily, Etf, ille, ltd, lc, lill) and lila, into the position illustrated in Fig. 6 the truing cycle is, stopped. in other words the mechanism is set, up. and arranged so that for each actuation of the push button starter switch EQ2, the trung tool 2d makes one complete re.- ciprocation passing across the operative faces of the. grinding wheel it toward the right and then returns toward the left into the starting position.

As the truing tool approaches the left hand end of its stroke,V the roller lil (Fig. 4) engages the caml race 59 to rock the pawl carrier E@ and the feed 'pawl lill to impart a rotary feeding movement to the ratchet wheel 5B thereby feeding the diamond or, truing tool 28 downwardly for the next. truing operation. if more than one complete reciprocaton of the truing tool across the wheel is desired, the push. button starter switch 262 may be again actuated to start a second cycle of operation. This procedure may be followed as many times as desired to obtain the desired truing operation on the operative face of the grinding wheel Il).

Thev` operation of this improved grinding wheel truing apparatus will be readily apparent from the foregoing disclosure. Assuming all of the parts to have been previously adjusted for a given truing operation, the fluid pressure pump lLll is started, the main switch 2 G is closed after which the push button starter switch 282 is actuated to initiate a truing cycle. As above explained the truing tool is intermittently indexed longitudinally toward the right in a manner above described to pass the truing tool across the operative faces of the various portions of the grinding wheel after which the diamond is fed downwardly before the truing tool 2E starts its return stroke toward the left. After the return stroke toward the left has been completed the mechanism stops. As the truing tool approaches the stop position, the truing tool is again fed downward in a manner above described so that it is for the next truing cycle.

During a truing cycle, the truing tool 2B moves rapidly toward the right until it approaches the face la of the grinding wheel it, at which time the valve ld is closed by action of the spring itil and the dog lill to slow down the movement of the truing tool 28 to a slow truing speed as governed by the throttle valve HH. Truing tool 28 traverses across the face Ida. of the grinding wheel it to true the same. When the truing tool 2% leaves ace lilo, the dog Isla (Fig. 6) opens the Valve H93 so that the slide I5 and truing tool 2t traverse rapidly across the gap between the wheel faces lila and ib. The cam bar l0 is then traversed toward the right so that the follower 2 rides down onto cam face 1lb. The truing tool then traverses across the face lllb of the grinding wheel IB after which the longitudinal movement of the slide l5 and the truing tool 28 stops and the longitudinal movement of the cam bar 'it starts further movement toward the right to raise the follower 'l2 into engagement with the cam face l lc. During this upward movement of the follower 'i2 the truing tool trues the shoulderedface between wheel faces Illb and 10c. This movement cycle of operation continues during f the traverse of the truing tool 23 and slide l5 toward the right. When the slide l5 approaches a right hand end position, the pawl carrier 5.9 engages a stop screw S3 to actuate the feed pawl S0 and causes a downward feeding movement of the truing tool 2B before the truing tool starts its traversing movement toward the left. After the slide reaches an extreme right hand end position, as illustrated diagrammatically in Fig. 9, the slide movement reverses and the slide l5 andthe truing tool 28 are traversed intermittently toward the left to again pass across the laces Illy, Ulf, le, lld., Hic., lb and lila to produce a further truing operation thereon. When the slide l5 and truing tool 28 approach the extreme left-hand end position as showny in Fig. 6, the roller 6l on the pawl carrier 59/ engages a cam face 68 to actuate the. feed pawl- Si) and cause a further downward feeding movement of the truing tool 28 ready for the next truing operation. As above explained for each actuation of the push button. starter switch 2v2, thev truing tool makes one complete reciprocation across the face of the Wheel and then stops. If further truing is desired,- it is necessary to again actuate thev push button starter switch 20.2 to` start another truing cycle.

It will thus be seen that there. has been provided by this invention a grinding wheel truing apparatusv in which the various objects hereinabove set forth together with many thoroughly aceituna practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it iS to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In a grinding wheel truing apparatus having a frame, a longitudinally movable slide on said frame, a transversely movable hollow sleeve on said slide, a truing tool holder therein, a truing tool mounted thereon, a feeding mechanism operatively connected between the holder and the sleeve to adjust said holder relative to said sleeve, means including a longitudinally movable cam on said slide and a follower on said sleeve which engages said cam successively to position the truing tool in a plurality of predetermined positions, means including a pair of independent uid motors one of which is operatively connected to traverse said slide and the other is operatively connected to traverse said cam, an electrically controlled valve means operatively connected to control said motors so as to alternately and successively traverse said slide longitudinally and said cam longitudinally relative to said slide intermittently to true a plurality of different diameters on a grinding wheel.

2. In a grinding wheel truing apparatus having a longitudinally movable slide, a transversely movable hollow sleeve on said slide, a truing tool holder therein, a truing tool mounted on the end of said holder, a feeding mechanism operatively connected to said holder to adjust said holder relative to said sleeve, means including a longitudinally movable cam slidably mounted on said slide and a follower xedly mounted on said sleeve in engagement with said cam, means including a fluid motor operatively connected to said slide intermittently to traverse said slide, and means including a fluid motor on said slide operatively connected to said cam intermittently to move said cam longitudinally relative to said slide when the slide is stationary successively to position the truing tool in predetermined positions on said slide for truing a plurality of different diameters on the periphery of a grinding wheel.

3. In a grinding Wheel truing apparatus having a longitudinally movable slide, a piston and cylinder operatively connected to said slide intermittently to traverse said slide longitudinally, a transversely movable hollow sleeve on said slide, a truing tool slidably keyed therein, a truing tool on the end of said holder, a nut and screw mechanism operatively connected to said holder for adjusting said holder longitudinally relative to said sleeve, means including a longitudinally movable cam slidably mounted on said slide and a follower in engagement with said cam which is fiXedly mounted on said sleeve, and means including a piston and cylinder on said slide operatively connected to said cam intermittently to move said cam longitudinally relative to said slide successively to position said holder and truing tool in predetermined positions for truing a plurality of varying diameters on a grinding wheel.

4. In a grinding wheel truing apparatus having a longitudinally movable slide, a piston and cylinder operatively connected thereto intermittently to traverse said slide, a transversely movable hollow sleeve on said slide, a truing tool holder slidably keyed therein, a truing tool mounted on said holder, a feeding mechanism onsaid sleeve which is operatively connected to said holder for adjusting it relative to said sleeve, means including a longitudinally movable cam slidably supported on` said slide anda follower engaging said cam which is xedly mounted on said sleeve successively to position the truing tool in a plurality of predetermined positions, means including a piston and cylinder on said slide which is operatively connected to said cam intermittently to traverse said cam longitudinally relative to the slide, and means including a hydraulic control valve mechanism operatively connected with said cylinders alternately and successively to admit fluid under pressure to the rst cylinder to traverse said slide longitudinally and to the second cylinder to traverse said cam longitudinally relative to said slide successively to position the truing tool for truing a plurality of different diameters on a grinding Wheel.

5. In a grinding Wheel truing apparatus having a base, a longitudinally movable slide thereon, a piston and cylinder operatively connected to the slide intermittently to traverse said slide longitudinally, a solenoid-actuated control valve operatively connected to said cylinder to control the passage of fluid under pressure to and from said cylinder, a transversely movable hollow sleeve on said slide, a truing tool holder slidably keyed therein, a truing tool mounted on the end of said holder, a feeding mechanism operatively connected between the sleeve and the holder to adjust said holder longitudinally relative to said sleeve, means including a longitudinally movable cam slidably mounted on said slide and a follower engaging said cam which is fixedly mounted on said sleeve, means including a piston and cylinder on said slide operatively connected to said cam intermittently to move said cam longitudinally relative to said slide successively to position said holder and truing tool in predetermined positions for truing a plurality of varying diameters on the grinding wheel, a second solenoid-actuated control valve operatively connected to the second cylinder to control the admission to and exhaust of fluid from said second cylinder, and means including a third solenoidactuated control valve operatively connected to said rst and second control valves successively to admit uid under pressure to the rst and second control valves so as to intermittently traverse said slide to true a wheel face and to traverse said cam to position the truing tool for truing the next wheel face.

6. In a grinding wheel truing apparatus, as claimed in claim 5, in combination with the parts and features therein specied of a limit switch on said slide, a serrated bar on said base which is arranged to actuate said limit switch by and in timed relation with the longitudinal movement of the slide to actuate the third solenoid valve to stop the longitudinal movement of the slide after it has moved through a predetermined distance and to start the longitudinal movement of the cam to reposition the truing tool for truing another portion of the grinding wheel, a second limit switch on said slide, and means including a serrated slide bar slidably supported on said slide which is actuated by and in timed relation with the movement of said cam to actuate the third valve to stop movement of cam bar and to start longitudinal movement of the slide to true a portion of the grinding wheel.

il'. I'na grinding wheel turing apparatus as claimed in claim 5, in-,combinationvvith thexparts and-features thereinspecied of alimt switch on said slide, a serrated slide har slidably supported on the base to actuate said rstl limit switch, adjustable stop screws on the, base to limit the endwise movement of said slide bar relative to the base to facilitate positioning the bar so that the limit switch is actuated at the same position of the slide during its movement in opposite directions to actuate the third solenoidvalve to stop the-longitudinal movement of the slide after it has moved through a predetermined distance and to start the longitudinal movement of' the cam to repositionA the truing toolv for truing` another portion of the grinding Wheel', a second limit switch on said slide, a longitudinally movable serrated slide barslidably supported' on said slide and movable Withy said cam to actuate said second-limitswitch, and adjustablefstop screws carried by the camxto facili,- tate endwise movement of said latterslide bar relative to the cam so that the second limit switch is actuatedy at the same positienof the cam bar during its movement in opposite directions;

8. In a grinding. Wheel truing apparatus, as claimedin claim 5, in cornoinationy with the parts and` features therein specified of a truingv cycle start switch operatively connected to energize the rst and second` solenoid-actuated control valves, a holding. circuit arranged to maintain said rst and second valves energized during movement of the slidel in one directionl so that when nuidunder pressure is passed thereto the slide and cam move intermittently in the same direction, a limit switch on the slide actuated by and in timed relation with the longitudinal movement of the slide to actuate the third solenoid-actuated control valve to stop the longitudinal movement of the slide afterv it` has moved through a predetermined distance andV to start the longitudinal movement ofthe cam to reposition the truing. tool for truing another portion oi the grinding Wheel, a second limit switch on said slide actuated by and in timed relation with the movement of said cam to actuate said third solenoid-actuated control valve to stop the movement of the cam and to startthe next longitudinal movement of the slide, and' a third limit 16 switch: actuated; bysaid slide at the end of its muvementfin one direction `todeenergize the first and, second,` control valves during the return stroke of; seid; slide soV that the direction of mov-ement,otneslideandcam are reversed on thereturn'stroke ofthe truing tool.

9 1 In, a grinding Wheel truing apparatus as claimed in claim 5, in combination With the parts and features therein specied of a pawl and ratchet' mechanism carried by said sleeve which is operativelyy connected tov actuate said feeding mechanism.,anyadjnstable screw to actuate said pawlwhen the slide;y reaches the end of its movement onedirection-.to advance the truing tool before; the, return movement of the. slide, and means,includingan'adiustable cam on said base to aetuatesaid pavvl When-,the slide reaches the end ofl itstraverseintheopposite. direction so asfto'advance-the truing tool for thenext trung cycle.

19, Ina grinding wheel` truing apparatus as claimed.infolaim5,L incombination with the parts and features thereinspeciiled of a manually oparable-)throttle valve operatively connected to the v first cylinder to control fluid exhausting therefrom seas-to control the speed of movement oi the nrst. piston-and the slide so as to control traversing speedofz` thetruing tool and an independent` manually. operable throttle valve operatively connected to the second cylinder to control fluid'exhausting therefrom so as to controlthespeed of movement ofv the cam.

OIVA E. HILL.

Rcferencesf'ited in the ille of this patenty UNITED STATES PATENTS FOREIGN PATENTS Country Date France Mar. 17', 1941 Number 1,932,969 1,965,535 l 2,010,37 5 2,1 50,09 l 2,219,264 2,335,207 2 ,433,027 2,435,32 l

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